Door skin, a method of etching a plate, and an etched plate formed therefrom

ABSTRACT

The present invention relates to a door skin comprising an exterior surface having outer portions lying on a first plane, spaced grooves recessed from the plane of the outer portions, and tonal portions having a planar area and a plurality of spaced depressions recessed from the plane of said planar area. The present invention is also directed to a method of etching a plate, for use with a molded die set, for embossing a wood grain pattern in the door skin, and the etched plate formed therefrom.

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM TO PRIORITY

This application is a continuation of U.S. application Ser. No.16/437,505, filed Jun. 11, 2019, now U.S. Pat. No. 10,597,931, which isa continuation of U.S. application Ser. No. 16/103,503, filed Aug. 14,2018, now U.S. Pat. No. 10,316,579, which is a continuation of U.S.application Ser. No. 15/665,898, filed Aug. 1, 2017, now U.S. Pat. No.10,047,556, which is a continuation of U.S. application Ser. No.15/238,024, filed Aug. 16, 2016, now U.S. Pat. No. 9,719,288, which is acontinuation of U.S. application Ser. No. 14/029,338, filed on Sep. 17,2013, now U.S. Pat. No. 9,416,585, which is a continuation of U.S.application Ser. No. 13/590,647, filed on Aug. 21, 2012, now U.S. Pat.No. 8,535,471, which is a continuation of U.S. application Ser. No.13/071,986, filed on Mar. 25, 2011, now U.S. Pat. No. 8,246,339, whichis a division of U.S. application Ser. No. 12/054,587 filed Mar. 25,2008, now U.S. Pat. No. 7,959,817, which is a division of U.S.application Ser. No. 10/753,862 filed Jan. 9, 2004, now U.S. Pat. No.7,367,166, which claims the benefit of priority of provisionalapplication No. 60/440,647 filed Jan. 17, 2003 the disclosures of whichare incorporated herein by reference and to which priority is claimed.

FIELD OF THE INVENTION

The present invention is directed to an interior or exterior passagedoor door skin or other molded article, such as wainscot, cabinet doors,moldings, trim products, paneling, millwork or the like, having anaturally appearing wood grain pattern formed in an exterior surface.The exterior surface has outer portions lying on a first plane, spacedgrooves recessed from the plane of the outer portions, and tonalportions simulating tonal changes as found in natural wood. The tonalportions have planar portions and a plurality of variably sizeddepressions recessed from the planar portions. The invention is alsodirected to a method of etching a plate, for use as an embossing plateor with a molded die set, for forming the wood grain pattern into theexterior surface of the door skin, a door formed from at least one andpreferably two of the resulting door skins, and the resulting etchedplate for providing an embossing plate or molded die set.

BACKGROUND OF THE INVENTION

Doors having compression molded door skins are well known in the art.Attempts have been made to provide a textured pattern on the exterior ofthe door skin to simulate the grain of natural wood. One such attemptprovides a printed wood grain pattern on the door skin. However, theprinted pattern has no depth or texture, as found in natural wood. Thevariable depth and texture found in natural wood provides a surfaceamenable to stain or other finishing. Therefore, staining and/orfinishing is not possible with printed door skins. Furthermore, theprint ink fails to simulate crisp wood grain ticks, and tick andbackground tonal variations.

Another attempt to simulate a natural wood grain pattern in the exteriorsurface of the door skin provides for transferring a photographic imageof the grain pattern into an embossing plate, by an etching process, toform a lower surface with raised ridges extending therefrom in theembossing plate. Etching is a process whereby areas of a metal plate arecovered with an acid resistant ground and an acid or mordant solution isapplied to the plate. The areas that have no resistant ground are eatenaway by the acid. An image or pattern is etched into the metal platethat then has a lower surface and a raised surface. Thus, the resistantground, or “resist”, controls where and how the acid eats into the metalplate. Chromed steel, copper and zinc are three most common metals usedfor embossing plates. Chromed steel is the hardest of the three metals,and will not wear down as quickly as non-steel plates after repeatedembossing.

Different acids are necessary for etching different metals. In addition,there are different resists and ways of applying the resists. There arealso various ways to expose the metal to the acid after the resist hasbeen applied so that tone and texture can be created. Acid treatment ofthe plate then etches out the uncoated metal, creating a texturedsurface in the embossing plate. Raised lines or ridges are created byetching into the plate around lines of protective resist. The acid theneats away at the unprotected portions of the metal plate, leaving theraised lines or ridges. These lines create the illusion of wood grainticks. The height of the lines is controlled by the width of thecorresponding line of resist that is removed.

Conventional etched plates may be used as an embossing plate or with amolded die set, for embossing and forming a molded article having thepattern on its exterior surface. As known in the art, the pattern may beformed in the article's surface by embossing or using a molded die set,and subjecting a substrate to selected amounts of heat, pressure andtime to form the molded article. When embossing a substrate to form adoor skin having a wood grain pattern, the embossing plate is pressedinto the material to provide bundles of wood ticks that form the grainpattern on the resulting door skin surface. A wood grain pattern is acluster or bundle of spaced, raised lines of metal, or “ticks”, whichextend in a pattern simulating the appearance of wood. The ticks must becarefully spaced to simulate a natural wood grain.

During etching, it is often difficult to achieve clear, crisp wood ticksbecause as the acid eats into the metal around the ticks, therebyforming gaps, it also eats into the side walls of the ticks. If adjacentgaps (defining a tick therebetween) are too closely spaced, the acid maysimply eat away at, and destroy the tick. As such, conventional etchedplates having wood grain patterns do not emboss highly realistic woodticks. In addition, such conventional etched plates often have sharpedges on the upper portions of the ticks, and undercuts at the bases ofthe gaps due to the nature of the etching process. If the gaps areetched too deep, undercutting often results since the acid has longer toeat away at the side walls of adjacent ticks as the gaps get deeper, ascompared to etching shallower gaps that do not require as much exposuretime to the acid.

In addition, conventional door skins with embossed wood grain patternsfail to capture the subtle wood tone variations found in natural wood.Natural wood includes not only wood ticks, but varying background tonesas well. It is the background tones and sharp, crisp ticks found innatural wood that provides the aesthetically appealing appearance, andthat enables it to be easily stained or finished. Conventional embossingplates used to form door skins with wood grain patterns fail to captureboth naturally appearing wood ticks and wood tones. If the door skinsurface is stained, it does not appear realistic. As commonly known inthe art, stains include a dye or pigment in solution, and are generallyused to color a wood by penetrating the wood surface. As such, thenatural wood tones and ticks may be enhanced or colored, without marringthe wood surface textures and tones, as with paint.

Stains do not penetrate the surface of a composite or polymeric doorskin in the same manner as natural wood. Therefore, attempts to stain acomposite or polymeric door skin for purposes of enhancing tones andticks is a difficult process for a typical consumer. The stain may notsimply be applied with a brush or rag, and the excess wiped off, as canbe done with natural wood. Rather, such door skins typically requiremultiple applications of stain, which must then be selectively removedby hand. This technique often requires a professional or one experiencedin staining in order to capture a natural wood appearance.Alternatively, portions of the door skin surface may be highlighted byspray gun application of the stain, or other shading material. The doorskin surface may be evenly sprayed, resulting in an unnatural, monotoneappearance. Even if the stain is carefully applied in specific areas,the resulting tones and wood ticks may appear splotchy and unrealisticif careful highlighting is not achieved. The average homeowner orconsumer is not sufficiently skilled to stain or finish such a moldeddoor skin, and achieve a realistic wood grain appearance usingcommercial stain finishing products. Therefore, there is a need for amolded door skin having a wood grain pattern that may be easily stained,and that precisely captures both the wood ticks and wood tones found innatural wood grain.

SUMMARY OF THE INVENTION

The present invention is directed to a molded door skin comprising anexterior surface having outer portions lying on a first plane, spacedgrooves recessed from the plane of said outer portions, and tonalportions. Each of tonal portions has a planar area and a plurality ofspaced depressions recessed from the plane of the planar area.

A method of etching a wood grain pattern into a plate comprises thesteps of: providing an image of a piece of wood having ticks andbackground tones; providing a metal plate; applying acid resist on asurface of the plate; laser ablating the resist according to a tickimage derived from the image; applying acid to the plate to form tickshaving a first height; repeating said applying acid resist, said laserablating and said applying acid steps to form other ticks having asecond height, wherein the second height differs from the first height;applying acid resist on the surface of the etched plate; laser ablatingthe resist according to a tonal image derived from the image; andapplying acid to the plate, thereby etching the plate and forming thetonal pattern in the plate.

The present invention also relates to an etched plate for forming a woodgrain pattern into a composition material. The etched plate has lowerportions lying on a first plane, spaced ticks extending from the planeof the lower portions, and tonal areas. The tonal areas have a pluralityof recessed channels, wherein said channels define a plurality of spacedprotrusions.

A molded construction component comprises an exterior surface havingouter portions lying on a first plane, spaced grooves recessed from theplane of the outer portions, and tonal portions. Each tonal portion hasa planar area and a plurality of spaced depressions recessed from theplane of the planar area.

A door comprises a peripheral frame, and at least one door skin, whereinthe door skin has an exterior surface with outer portions lying on afirst plane, spaced grooves recessed from the plane of the outerportions, and tonal portions. Each tonal portion has a planar area and aplurality of spaced depressions recessed from the plane of the planararea.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front elevational view of a door skin having a wood grainpattern according to the present invention;

FIG. 2 is a first embodiment of an enlarged perspective view of thecircled portion 2-2 of FIG. 1;

FIG. 2A is a second embodiment of an enlarged perspective view of thecircled portion 2-2 of FIG. 1;

FIG. 3 is an enlarged perspective view of the circled portion 3-3 ofFIG. 1; and

FIG. 4 is a fragmentary perspective view of an etched metal plateaccording to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a door skin D having a naturallyappearing wood grain pattern formed in an exterior surface 10, as bestshown in FIG. 1. The wood grain pattern may be formed using an etchedplate, such as in an embossing plate or molded die set, or other processknown in the art. As best shown in FIG. 2, exterior surface 10 of doorskin D comprises a plurality of spaced grooves 12 that are formed intoexterior surface 10, and simulate wood ticks as found in natural wood.Each one of grooves 12 is defined by opposing walls 14 and a base 16. Aplurality of outer portions 18 lie on a first plane that includes themost exteriorly disposed surfaces of exterior surface 10. Interfaces 15interconnect and are integral with outer portions 18 and walls 14.Preferably, interfaces 15 are curved. Outer portions 18 separateadjacent grooves 12. Preferably, grooves 12 are recessed from the firstplane from between about 0.005 inches to about 0.015 inches, and mayhave variable widths and depths. As such, outer portions 18 may alsohave variable widths, as best shown in FIG. 2. The depth of grooves 12may vary beyond this range depending on the substrate used to form doorD, as well as the wood species being simulated. For purposes ofexplanation, the depths described herein simulate a wood grain patternsuch as found in ash wood.

Adjacent grooves 12 may be spaced from each other by variable distances,and extend longitudinally relative to each other by variable lengths, asshown in FIG. 1. Grooves 12A, 12B and 12C are spaced from each other,extending in an arrowhead-like configuration, as may be found in naturalwood. Grooves 12D, 12E and 12F extend longitudinally, extending theentire length of door D. It should be understood that the configurationof grooves 12 simulates natural wood. As such, while some grooves 12 mayextend substantially parallel and spaced a predetermined distance, theyneed not, as shown in FIG. 1. Thus, the configuration of grooves 12simulates an appearance of soft, flowing wood ticks.

In addition, exterior surface 10 includes tonal portions 20. Each one oftonal portions 20 includes a planar area 22, and a plurality of spaceddepressions 24 recessed from the plane of planar area 22. Each one ofdepressions 24 includes a base 25 and sides 27. As shown in FIG. 2,depressions 24 appear as open box-like recesses, or pockets, having asubstantially square configuration. However, depressions 24 may alsohave a cylindrical configuration. The bases 25 of depressions 24 arepreferably recessed from the plane of planar area 22 from between about0.001 inches to about 0.003 inches. However, the depth of depressions 24may vary beyond this range depending on the substrate used to form doorD, and the wood species being simulated. Preferably, depressions 24 arerecessed from the plane of planar areas 22 by about the same depththroughout exterior surface 10. Planar areas 22 preferably lie on aplane that is coplanar with the plane of outer portions 18.Alternatively, planar areas 22 may be slightly recessed from the planeof outer portions 18.

Depressions 24 are variably spaced throughout planar areas 22, and mayalso be variably sized. As such, the density and size of depressions 24in one planar area 22 may differ from the density of depressions 24 inanother planar area. When stain is applied to exterior surface 10,larger depressions 24 retain more stain than smaller depressions 24,resulting in a darker tonal area in a planar area 22 having largerdepressions 24. Furthermore, a planar portion 22 having a relativelyhigh density of depressions 24 retains more stain than a planar portion22 having a relatively low density of depressions 24. Again, a higherdensity of depressions 24 create a darker tonal area on exterior surface10. In this way, tonal variations are precisely controlled, achievingsubtle background tones as found in natural wood. In addition, someplanar areas 22 may include no depressions 24, as best shown in FIG. 3.This provides a bi-color or glossy appearance after stain is applied toexterior surface 10.

Therefore, exterior surface 10 of door skin D includes a plurality ofgrooves 12 and tonal portions 20, which together simulate wood ticks andbackground wood tones as found in natural wood grain. When stain isapplied to exterior surface 10, varying amounts of stain accumulate ingrooves 12, since grooves 12 are variably spaced and have variablewidths and depths. Deeper, wider grooves 12 hold more stain as comparedto shallower, narrower grooves 12. In this way, deeper grooves 12simulate darker, more prominent wood ticks. Similarly, shallower grooves12 simulate lighter, more delicate wood ticks. Likewise, a tonal portion20 having a high density of depressions 24, or larger depressions 24,retains more stain as compared to a tonal portion 20 having a lowerdensity of depressions, or smaller depressions. The more stain that isretained in a tonal portion 20, the darker the area will appear. Thus,varying tonal portions 20 simulate varying wood tones, depending on thedensity and size of depressions 24.

Stain may be easily applied to exterior surface 10 of door D by an enduser by simply wiping the stain on exterior surface 10. The integrationand configuration of grooves 12 and tonal portions 20 allow the stain tobe simply wiped or brushed on by the consumer. The stain clings andcongeals in the recessed areas creating small pools of stain. Thevarying depths and sizes of grooves 12 and depressions 24 create tonalvariations more closely approximating natural wood. Excess stain is thenwiped off. Thus, stain is applied to the disclosed molded door skin D inthe same manner as it is applied to natural wood. Furthermore, only onecoat of stain may be required, depending on the preference of the enduser. Preferably, a heavily pigmented stain is used, which will easilycling and congeal in grooves 12 and tonal portions 20.

The present invention is also directed to an etched plate P, for use asan embossing plate or with a molded die set, for forming a wood grainpattern in the exterior surface of a molded article, such as door skinD. As best shown in FIG. 4, a metal plate P includes multi-level ticksintegrated with tonal areas. Specifically, plate P includes a pluralityof etched ticks 30 extending upwardly from lower portions 32, whereinlower portions 32 lie on a plane that include the deepest etchedsurfaces of metal plate P. Ticks 30 have a ridge-like configuration, andvary in height from between about 0.005 inches to about 0.015 inches.The height of ticks 30 may vary depending on the particular wood speciesthat is being simulated. Each one of ticks 30 includes an upper ridge34, and walls 36 extending from upper ridge 34 to lower portions 32.Adjacent ticks 30 are separated by gaps 38, which are etched into plateP to define ticks 30. Plate P has an inverse configuration to theexterior surface being formed in door D. For example, ticks 30correspond to grooves 12 of door D, and the plane of lower portions 32corresponds to the first plane of outer portions 18 (and planar area22).

Plate P also includes tonal areas 40, which correspond to tonal portions20. For example, tonal areas 40 correspond to tonal portions 20 of doorskin D. Tonal areas 40 include a plurality of recessed channels 42.Channels 42 are configured in a grid-like pattern, define a plurality ofspaced protrusions 44. Spaced protrusions 44 are preferably box-shapedin configuration (as defined by the grid-like pattern of channels 42).However, spaced protrusions 44 need not be box-shaped. For example,tonal areas 40 may include a plurality of cylindrically-shapedprotrusions. Each one of spaced protrusions 44 includes a flat top 46,and sides 48 extending from and integral with flat top 46 and a base 50of channels 42. Bases 50 of channels 42 are preferably coplanar with theplane of lower portions 32. Alternatively, bases 50 of channels 42 maybe slightly raised above lower portions 32.

Spaced protrusions 44 extend upwardly from channels 42 to a height ofbetween about 0.001 inches to about 0.003 inches. The density, size andspacing of protrusions 44 in a given tonal area 40 are variable. In thisway, variously sized and spaced depressions 24 are formed in tonalportions 20 (through embossing or molding), resulting in tonalvariations in exterior surface 10 of door skin D (or other moldedarticle) when stain is applied. Thus, protrusions 44 create depressions24 that act as pockets or cells to retain stain. Similarly, ticks 30create grooves 24 of variable depths and widths (since ticks 30 havevariable heights and widths). Deeper, wider ticks 30 create deeper,wider grooves 12, which retain more stain than shallower, narrowergrooves 12. Thus, tick colorations and tones, as well as backgroundtones, are precisely controlled using the disclosed etched plate. Thetextured surface created by plate P simulates the surface of naturalwood, forming molded articles having a textured surface that is easilystainable, wherein the stain may be simply wiped on by the consumer inone stain application.

The present invention also relates to a method of etching a plate, foruse as an embossing plate or molded die set, for forming a moldedarticle, such as door skin D, with a naturally appearing wood grainpattern formed in an exterior surface of the molded article. First,natural wood planks having a desired wood grain pattern are selected.The planks may be any desired species of wood. Preferably, each woodplank is a component of a door or panel that is to be simulated by themolded article, such as a stile, rail or panel. The planks arephotographed, preferably digitally, to derive the actual texture, toneand wood grain pattern of the natural wood plank. To enhance the imageof the ticks and tones, the planks may be sanded and finished with aclear lacquer coat before photographing.

After capturing the images of several wood planks representing all ofthe components of the molded article, the resulting images are digitally“assembled” to create an image of a door, a panel, or the like. Forexample, images of planks corresponding to stiles, rails and panels maybe digitally aligned to create an image of a door. This door layoutimage will provide the wood grain pattern for the molded door skin. Theplanks may be of different wood species, so that the stiles and railsmay simulate one species and the panels another species. In addition,the wood grain pattern of each plank may be oriented as desired whenassembling the door layout image. The resulting door layout image has ahighly realistic wood grain pattern, with the wood grain of the stilesoriented perpendicular to that of the rails, and the wood grain of thepanel(s) oriented as desired. Alternatively, the wood grain image may beformed only in the flat surface areas of the door skin D, and not in themolded contour portions. Thus, an image of how a door would appear ifactually constructed from the natural wood planks is digitallyconstructed. Alternatively, the wood planks comprising all of the doorcomponents (i.e. stiles, rails and panels) may be arranged as if thedoor were constructed, and an image of the entire plank layout captured.

The resulting layout image is separated by computer software, such asavailable with Photoshop™ into a series of layering images. Eachlayering image is an image of the ticks, wherein widths have beenadjusted based on tick depth (in the wood planks). The depth of theticks from the wood planks is determined by a computer program, whichcorrelates the shades and colorations of ticks in the initial layoutimage to a particular tick depth. The deepest ticks from the planks(i.e. ticks having the darkest, widest appearance in the initial image)are formed having the greatest height (relative to lower portions 32)during the etching process. Preferably, the ticks range in heightrelative to the deepest etched portions of a metal plate P from betweenabout 0.005 inches to about 0.015 inches. This is the preferred range ifsimulating a wood species such as ash. This range may vary depending onthe substrate being molded and the species of wood being simulated. Thetotal etching depth (i.e. corresponding to the tick height range) istherefore predetermined.

Preferably, the initial layering image is separated into at least 2layering images, more preferably at three layering images. However, itshould be understood that more layering images may be used, such aseight layering images. Each layering image corresponds to an etchingcycle. Thus, the more layering images that are used, the more etchingcycles the plate undergoes.

When simulating a wood species such as ash, three layering images arepreferred. The first layering image is an image of only the deepestticks (as determined by the computer). The second layering image is animage of the same tick pattern of the first layering image, but theimage has been modified to narrow the ticks in the image. As known inthe art, the depth of a particularly etching cycle (and therefore heightof the ticks being formed) is a function of the width of resistprotecting the ticks. Similarly, the width of the ticks is controlled bycontrolling resist removal. Thus, the number of etching cycles, andresist removal, is correlated to the particularly type of wood speciesbeing simulated. For example, oak has relatively wide ticks, and theetch depth for the ticks can therefore be greater than for therelatively thin ash ticks.

In a preferred embodiment for simulating a wood species such as ash, theinitial image is separated into three layering images and four etchingcycles to create ticks 30. Using four etching cycles, ticks 30 aregradually etched into plate P. Preferably, metal plate P is copper.Copper has an extremely fine micrograin structure and therefore allowsfor precision etching, forming closely spaced, narrow ticks 30. Morepreferably, 20 gauge copper is used. However, other metals may be used,such as aluminum, cold rolled steel and stainless steel. After the plateis etched, it may then be attached to a steel die to provide supportwhen used as an embossing plate, or with a molded die set. The metalshell may be fastened mechanically to the steel die face. Alternatively,etched components may be attached to a steel die or mold.

Prior to etching, the plate is thoroughly cleaned. Then, a first resistcoating is applied to the surface of the plate. Preferably, the resistis a lacquer-based resist, such as that used by Wood Graphics ofCincinnati, Ohio. The resist is sprayed onto the surface of the plate toa thickness of about 4-6 microns. After the plate has been prepared withthe resist, an image corresponding to the first layering image is laserablated into the resist. The first image is an image of the deepestticks. The resist may be precisely removed using the laser. The coatedplate is then subjected to acid. Preferably, a ferric chloride basedacid is sprayed onto the surface of the plate, such as that used by WoodGraphics of Cincinnati, Ohio. It should be noted, however, that the typeof acid used varies depending on the type of metal being etched. A firstlevel of etching eats into the surface of the plate to a depth of about0.004 inches. As known in the art, the amount of time required for acidetching is a function of depth desired, as well as the strength of acidused. After the first etching cycle is complete, the plate is thoroughlycleaned with an alcohol-based cleaner to remove any remaining resist oretching residue.

The plate is then subjected to an acid bath. Preferably, a ferricchloride based acid is used, as used in for the first etching cycle. Theacid bath rounds off any sharp edges formed during the first level ofetching. Preferably, any sharp edges are rounded down (i.e. eaten awayby the acid) by about 0.001 inches.

The plate is then washed to remove any acid and/or particulates, andprepared for the second etching cycle. Preferably, the resist and acidused for the all etching cycles is the same. A second resist coating isapplied to the plate, covering the entire surface of the plate(including portions that were etched in the first etching cycle).Thereafter, an image corresponding to a second layering image is laserablated into the resist. The second layering image is an image of thetick pattern from the first layering image, but the ticks have beennarrowed (i.e. the resulting ticks have reduced widths). The laserablation removes the resist according to the pattern of the secondlayering image.

Because the ticks are narrowed in the second layering image (compared tothe first layering image), only the resist at the base of the tickspreviously etched is removed, leaving resist on the sides of the ticksprotected, such as side walls 36. This exposes the lower portion (i.e.32) of the gaps (i.e. 38) being etched, so that etching may continue inthose areas (i.e. resulting in deeper gaps). However, the resist coatsand protects the sidewalls of the ticks being formed, which ultimatelycreates delicate, closely spaced ticks. In addition, undercutting iseliminated, since the sides 36 are protected. Thus, the bases of thedeeper gaps are exposed for continued etching, thereby increasing theheight of ticks (for deeper embossing). The second etching cycle etchesinto the plate an additional 0.003 inches.

The plate is again cleaned and prepared for the third etching cycle. Athird resist coating is applied, preferably the same resist as used inthe other etching cycles. The second layering image is used as a patternfor resist removal during the third etching cycle. The resist is againlaser ablated according to the second layering image, and the plate isetched an additional depth of 0.004 inches.

Then, the plate is again thoroughly cleaned, and the plate is subjectedto a fourth etching cycle. The third layering image is used as a patternfor resist removal during the fourth etching cycle. The third layeringimage is an image of the deeper ticks, as well as the shallower ticks.Therefore, the bases of the deeper gaps (defining the highest ticks) areincreased. In addition, shallower gaps (defining ticks having a lowerheight) are etched into the metal, thereby creating a multi-level tickconfiguration. Resist is removed by laser ablation, as described above,and the plate is subjected to acid. The fourth etching level eats intothe plate an additional 0.002 inches.

During the four etching cycles described above, planar areas are alsoetched into the metal, which will correspond to tonal portions 40. Assuch, these planar areas are etched to a depth of between about 0.012inches to about 0.014 inches (which is the total depth etched duringetching cycles 1-4).

A fifth and final etching level completes the etching process. However,this final etching process is unique in that a different image is usedas the pattern for resist removal. Specifically, the plate is subjectedto a gravure screen etching process to create tonal portions 40, andfinalize the depth of gaps 38 defining ticks 30. The screen process usesthe initial layout image described above, combined with a gravure screento create a screened image. The screen permits a digital manipulation ofthe initial image, wherein the initial image is broken down into aplurality of variably sized squares, much like a grid overlying animage. The grid is not composed of equally sized and spaced squares.Rather, larger sized squares correspond to darker areas of the initialimage. The darker the density of the image, the larger the size of thesquare, and vice versa. Preferably, a screen having 133 to 200 lines perinch is used, more preferably a 150 line screen is used for simulating awood grain pattern such as ash wood. A 200 line screen providesincreased detail in the etching process. However, a screen having fewerlines per inch, such as a 133 line screen, may provide a better releasefrom the metal die after the door skin is embossed and pressed. Theresulting screened image includes a series of squares corresponding totonal variations in the initial image. Darker tones correspond to largersquares having a higher density in a given area. Lighter tonescorrespond to smaller squares having a relatively lower density in thegiven area.

Before etching the plate in the fifth etching cycle, the plate is againcleaned to remove any remaining resist or particulates. Then, the plateis coated with resist, which is preferably the same resist as used forthe other etching cycles described above. The resist is removedaccording to the pattern provided by the screen image, and removed bylaser ablation. In the areas forming tonal portions 40, the resist isremoved in areas corresponding to channels 42, leaving squares of resist(thereby creating protrusions 44).

In the areas forming ticks, all resist is removed except for lines ofresist protecting those ticks having the greatest height. The etchedplate is then subjected to a fifth acid etching cycle, eating into theplate an additional depth of between about 0.001 inches to about 0.003inches. Preferably, this is the final etching cycle. However, the platemay be subjected to two relatively short screen etching cycles.

The five etching cycles create a multi-level structure in the plate, andachieve delicate, closely spaced ticks. Preferably, the plate is etchedto a depth of 0.005 inches or less during each etching cycle. (As noted,acid etching time is a function of depth). In this way, undercutting ofthe ticks is eliminated. In addition, well defined, closely spaced ticksare formed.

The etched plate, for use as an embossing plate or with a molded dieset, forms a molded article, such as door skin D, having a surface thatprecisely simulates the qualities of natural wood. Although thedisclosed wood grain pattern has been described with reference to amolded door skin D, it should be understood that the present inventionis applicable to a wide range of molded and/or embossed articles, suchas cabinet doors, furniture doors, millwork, wainscot, paneling,construction components, decorative moldings, trim products, and thelike.

In addition, the disclosed depths and heights of surfaces describedherein are the preferred ranges for simulating a wood grain pattern suchas food in ash wood. It should be understood that these preferred rangesmay vary depending on the substrate used to form the molded article, andthe species of wood being simulated. For example, it may be desirable toincrease tick and tonal depths when forming an article molded from aharder substrate, such as hardboard, in order to achieve the desiredtonal variations.

Preferably, the molded article is compressed from a polymer-basedcomposite, such as sheet molding compound (“SMC”), polystyrene orpolypropylene. However, other substrates may be pressed or embossed withthe disclosed etched die, including medium density fiberboard,hardboard, fiberboard, steel, other wood composite materials, and otherthermoplastic materials.

It will be apparent to one of ordinary skill in the art that variousmodifications and variations can be made in construction orconfiguration of the present invention without departing from the scopeor spirit of the invention. Thus, it is intended that the presentinvention cover all modifications and variations of the invention,provided they come within the scope of the following claims and theirequivalents.

1-50. (canceled)
 51. A door, comprising a peripheral frame; and at leastone door skin attached to a side of the peripheral frame, the door skinhaving a stainable exterior surface comprising stiles, rails, and panelswith molded grooves and molded tonal portions stainable with a stain,the molded grooves of the at least one door skin configured withvariable depths and lengths relative to one another and variably spacedwith respect to one another to collectively simulate an appearance of anaturally appearing wood grain tick pattern, the molded tonal portionsof the at least one door skin comprising depressions configured toreceive and retain sufficient stain to simulate an appearance ofdarkened naturally occurring wood grain background tone.
 52. The door ofclaim 51, wherein a first area of the stainable exterior surface has afirst density of the molded tonal portions, wherein a second area of thestainable exterior surface has a second density of the molded tonalportions, and wherein the first density differs from the second densityso that when stain is received and retained in the molded tonal portionsthe first and second areas simulate naturally occurring wood backgroundtones having different degrees of darkness.
 53. The door of claim 51,wherein the molded grooves have a greater depth than the depressions.54. The door of claim 51, wherein the at least one door skin comprises asheet molding compound, polystyrene, or polypropylene.
 55. The door ofclaim 51, wherein the at least one door skin comprises medium densityfiberboard or hardboard.
 56. The door of claim 51, wherein the moldedgrooves extend parallel to one another.
 57. The door of claim 51,wherein the stainable exterior surface further comprises outer portionslying between the molded grooves.
 58. The door of claim 57, wherein theouter portions are planar with one another, and wherein the grooves arerecessed from the outer portions by between about 0.005 inch to about0.015 inch.
 59. The door of claim 51, wherein the molded tonal portionsform an outer planar area.
 60. The door of claim 59, wherein bases ofthe depressions are recessed between about 0.001 inch and about 0.003inch from the outer planar area.
 61. A door, comprising a peripheralframe; and first and second door skins attached to opposed sides of theperipheral frame, each door skin having a stainable exterior surfacecomprising stiles, rails, and panels with molded grooves and moldedtonal portions stainable with a stain, the molded grooves of the atleast one door skin configured with variable depths and lengths relativeto one another and variably spaced with respect to one another tocollectively simulate an appearance of a naturally appearing wood graintick pattern, the molded tonal portions of the at least on door skincomprising depressions retaining a sufficient amount of the stain tosimulate an appearance of darkened naturally occurring wood grainbackground tone.
 62. The door of claim 61, wherein a first area of thestained exterior surface has a first density of the molded tonalportions retaining a first amount of the stain to provide a first tone,wherein a second area of the stained exterior surface has a seconddensity of the molded tonal portions retaining a second amount of thestain to provide a second tone, and wherein the first tone differs fromthe second tone to simulate multiple naturally occurring wood backgroundtones of different degrees of darkness.
 63. The door of claim 61,wherein the molded grooves have a greater depth than the depressions.64. The door of claim 61, wherein the door skin comprises a sheetmolding compound, polystyrene, or polypropylene.
 65. The door of claim61, wherein the door skin comprises medium density fiberboard orhardboard.
 66. The door of claim 61, wherein the molded grooves extendparallel to one another.
 67. The door of claim 61, wherein the stainedexterior surface further comprises outer portions lying between themolded grooves.
 68. The door of claim 67, wherein the outer portions areplanar with one another, and wherein the grooves are recessed from theouter portions by between about 0.005 inch to about 0.015 inch.
 69. Thedoor of claim 61, wherein the molded tonal portions form an outer planararea.
 70. The door of claim 69, wherein bases of the depressions arerecessed between about 0.001 inch and about 0.003 inch from the outerplanar area.